{
  "abstract": "Strong-deflection lensing by a subextremal Kerr black hole exhibits a logarithmic critical divergence, whereas the exactly extremal prograde problem develops stronger power-law behavior. We construct a uniform asymptotic description of the transition between these regimes for prograde equatorial null geodesics. The distinguished joint near-critical and near-extremal limit occurs when the impact-parameter offset from the exact critical value is of order \\(Mκ\\), where \\(κ=\\sqrt{1-a^2/M^2}\\). In this limit, the Kerr radial potential reduces to a quadratic normal form, yielding an analytic crossover function that connects the subextremal logarithmic and extremal power-law regimes. We derive a matched next-to-leading-order correction and validate it against high-precision integrations of the exact Kerr geodesic equations, finding improvement for all 55 trajectories tested. The same asymptotic structure yields a higher-order image-branch law interpolating between algebraic and exponential accumulation, with crossover order scaling as \\(κ^{-1}\\). We also derive and numerically validate the corresponding image-branch coordinate-time delay law, whose high-order extremal-like limit approaches the horizon-period spacing \\(4πM\\).",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.02900",
  "author_total": 1,
  "authors": [
    {
      "name": "Shakibul Chowdhury"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5xf208vfa6g1g.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.02900",
  "fulltext_url": null,
  "id": "5xf208vfa6g1g",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.02900",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Astrophysical Phenomena and Observations"
    ]
  ],
  "openalex": "W7220464052",
  "pdf_url": "https://arxiv.org/pdf/2610.02900",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5xf208vfa6g1g.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:45Z",
      "native_id": "2610.02900",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.02900"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Uniform Strong-Deflection Lensing in Near-Extremal Kerr",
  "title_text": "Uniform Strong-Deflection Lensing in Near-Extremal Kerr",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:45Z",
  "url": "https://research.draconitic.com/paper/5xf208vfa6g1g",
  "venue": "arXiv",
  "versions": []
}